Process of revivifying gas-purifying materials.



. j PATENTED FEB. 5, 190-7. H. L. DOHERTY. I f I PROCESS OF REVIVIFY-INGGAS PURIFYING MATERIALS.

-- APPLICATION FILED I 10V. 12, 1906.

INVENTOR.

Hem AgQ' I f B)- LDC M Q-QL m aem [1 TTORN/j rs UNITED srA'rns PATENT orries.

HENRY L. DOHERTY, MADISON, WISCONSIN.

PROCESS OF REVlVIFYlN' -G GAS-PURIFYING MATERIALS.

Specification of Letters Patent.

Application filed November 12, 1906. Serial No. 343,054.

Patented Feb. 5, min.

scription of the same, such as will enable others'skilled the art to which it appertains to make and use the same.

This invention relates to revivifying purifying materials, and consists in a method of regulably oxidizing and revivifying spent metallic oxids and salts used for the removal and recovery of sulfur from'gases, oils, and other sulfur-bearing materials, all as more fully hereinafter set forth and claimed.

Many of the heavy metal oxids and their salts when contacted .with sulfur-bearing gases and oils remove the sulfur, part of it generally being deposited as such and the remainder entering mto combination with the metal to form sulfid. Lighting-gas, for instance, is generally freed from sulfur by the so-called Laming s mixture, f a mixture of iron oxid and sawdust, the sawdust merely serving to maintain porosity. Upon exposure to sulfur compounds of the type of hydrogen sulfid the oxygen of the oxld unites With the radical with which the sulfur iscombined, part of the sulfur being deposited as such and the residue forming iron sulfid. Being formed at a low temperature in the presence of moisture, this sulfid is excessively oxidizable and on exposure to oxygen reforms the oxid with deposition of the sulfur existing in the form of sulfids as free sulfur .if the operation be carefully performed.

Many other heavy metal oxids may-be used in lieu of iron oxid, as may their salts. Ferrous or cupric sulfate, for instance, takes u ammonia from gas to form ammonium su fate, and then the residual oxids perform the described reaction, or with gas containing little or no ammonia the metallic salt may be mixed with base, such as lime, inthe first lace. With salts of such weak acids as oric and the like no base need be used. The advantage in using .salts in this operation resides only inthe fact that they furnish on decomposition at low temperatures hydratedoxids, which are much more reactive with sulfur compounds than oxids which have been exposed to high temperatures or are-in aged forms, formswhich have suflered intramolecular condensation. Such, aged forms are readily produced with most oxids at temperatures not far removed from 100 centigrade. Copperhydrate, for instance, dehydrates and assumes an aged comparatively non-reactive form when placed 1n boiling Water.

In freeing gas and petroleum from sulfur it is highly important that the metallic oxids employed be in as reactive a form as possible an that when recovered for reuse .they be not exposed to high temperatures. Low-temperature recovery is also necessary, because the sulfurmixed with the oxid must not be allowed to melt and clog the pores of the re-' acting mass but, as stated, the sulfids formed in the sulfur removal are themselves in a highly reactive condition and on exposure to air rapidly oxidize with development of high dation being almost infinite.

Removal of the spent oxids from the purifyingboxes and exposure to air in thin layers wet down at intervals accomplishes the re- 7 5 temperatures, the surface they expose to oxi sultin a measure, but is a very offensive op.- eration, because of the evolution ofbadsmelling gases. Revival in the boxes is very 'apt to lead to undue temperatures. Attem ts have been made to temper the air used or such revival with steam; but this of course means high temperatures.

In the present invention,diagrammatically illustrated. in the accompanying. drawing, which shows a diagrammatic partly-sectional elevation, I have devised a method of revivifymg such spent oxids directly in the purifylug-boxes by theuse of air-currents ofregulated composition and temperature, and in the accompanying illustration I have shown one ty e of apparatus of the many adapted to pe orm myprocess and accomplish myresults.- V

In this apparatus, which, as shown, is more particularly adapted to holding and treating Lamings mixture for purifying gas,

but may be also used for holding copper oxid and the like. for treating sulfurous oil, 1 is a purifier-box, such as may be used for purify- .ing gas, and is provided with a'seal 2, cover 3, a- Water-introducing pipe or means 4, a layer or purlfymg OXldS or material 5, and a false bottom 6 to support the same. In normal operation gas tobe purified enters through pipe 7 and passes throu h the mate'- rial 5 and out throu h pipe .8. n purifying the gas so passing t ough it the material dually becomes feui and loses itvsflplotency the plpe carries a valved outlet or inlet 11,

.having a o ening to the atmosphere, and said ipe is also connected to the suction side of a an 12, pipe '13, provided with another valved inlet or outlet 14 and also connected, through a heater 15,'with the outlet-P pe 8 of the purifier. Suitable valves 16- and 17 in the outlet andinlet pipes 8 and 7 of the purifier allow it to be thrown out of circuit of gas to be purified and a circulatory motion of ases to be reduced therein by the fan. alves 18 and 19 allow this circulation to be controlled. Thermometers 20 are provided to ascertain the temperature in the purifyingbox. In practice the same revivifying apparatus is usually connected by suitable plpes and valves to a number of purifying-boxes 1 such as shown, in such manner that any one of the purifying-boxes may be'th'rown out .of

serviceand connectcdvto the revivifying apgaratus and its purifying material revivified. uch pipe connections will be readily understood by those skilled in the art. They are omitted here for the sake 'of clcarness and simplicity of illustration.

In use after connectmg the revivifying apparatus operatively to a box 1 by closing valves 16 and 17 and opening valves 18 and 19 the residual gas remaining in the-purifier is started into circulation by the fan, a minimal amount of air being allowed to mix therewith through valve 11 on the suction side of the fan and alittle' as allowed to waste through 14. The circu ating gas mass is thus an excessively dilute air. The oxygen of this air is absorbed to oxidize the sulfid and the temperature tends to rise, this tendency being restrained by use of the cooler. In each traverse of the circuit a little air is admitted and a little gas discharged. The discharged gas at first is mostly the residual gas left in the purifier at starting, but becomes nearly pure nitrogen a little later. The feed of air is of course inversely proportioned to the observed tendency to rise in temperature in the purifier. ing out of the mixture or dehydration of the oxids, water is admitted to the purifierin small amounts. Toward the end of the reaction, when the sulfids are nearly all. oxidized, the reaction tends to slacken, and the proportion of air must be increased and the eater brought into function. The temperature in the purifier, however, should at no time be allowed to exceed 120 Fahrenheit with the ordinary Lamings mixture and is preferably kept at about Fahrenheit.

1tio1f of su necessary to. extract sa1d sulfur.

In order to prevent dry-- (ziperating in the manner described the oxi s are perfectly revivified at low temperature, retalning all their activity and having no chance topass into aged comparatively little-reactive form. The mass retains its porosity, and .no local overheatin occurs to melt the sulfur or damage the oxi s, nor is it necessaryto remove the purifying materialfrom the purifier-boxes until the accumulafur due to repeated use renders it In practice the apparatus shown is of course connected to a plurality of purifiers,

' in which the purifying mass is to be used and recovered successively.

The particular purifyin box 1 illustrated is'of my invention and orms the subject matter of another application for Letters. Patent, Serial N01 343,055, filed November 12, 1906. However, ;my invention is not re-' stricted to the'use of this particular or of any particular purifyin box. Hence I do' not describe the particu ar box illustrated in detail. i

I do not limit myself to any articular type of heater or cooler to be used 1n the apparatus for carrying out the above process.

The particular cooler shown is one in which the gases pass through a series of pi es, around which coclin fluid is circulate but any other suitab e cooler .may be used. The

heater shown is one in which the gas cirulates around pipe-coils through which heated fluid or gas is passed; but I may use any other type of heater'-as,,for example, one in which the heating is effected by blowing steam into the gases-and sometimes I may use both the heat-coils and a steam-inlet, as shown at 21 What I claim is 1. The process of recovering spent,purifying oxids which consists in reoxidizing with a regulated current of air diluted with gases.

2. The process of recovering spent purifying oxids which consists in reoxidizing with a regulated current of air diluted with gases,

the dilution being proportional to the ob served tendency to rise in temperature.

3. The process of recovering spent purifying oxids which consists in circulating a gas mass throu h said oxids in closed circuit and progressively adding increasing amounts of air to said gas. mass. 1

4. The process of recovering spent purifying oxids which consists in pro ducing a closed circulation of an indifferent gas mass bathing said spent oxids, removing a portion of said gas at one point in the circulation and replacing it with aportion of air, and contin 'uing the intro duction of air and removal of excess gas until the oxidation of the spent oxids is complete.

5. The process of recovering spent oxids which consists in producing a closed circulation of an indifferent gas mass bathing said spent oxids and-gradually replacing it with air, the introduction of air being inversely proportional to theobserved tendency of the spent oxids to rise in temperature.

' 6. The process of recoveri spent oxids which consists-in producing a c osed circulation of an indifferent gas mass bathing said veloped heat being removed by a cooling despent oxids and gradually replacing it with air, the introduction of air, being inversely proportional to the observed tendency of the spent oxids to rise in temperature, and device placed in the gas-circuit.

7 The process of recovering spent oxids which consists in reoxidizing said spent oxids with a cooled, diluted air-current S. The process of recovering'spent oxids which consists in reoxidizing with a regulated current of cooled diluted air, the dilution being proportional to the observed tendency of the spent oxids to rise in temperature, and finally finishing the oxidation with warmed air.

9. The process of recoverin spent oxids which consists in producing a c osed circulation of an indifierent gas mass bathingsaid spent oxids, removing a portion of the gas at one point in the circuit and replacing it with a portion of air, the amount of air introduced being inversely proportional to "the observed tendency of the spent oxids to rise in temperature, removing developed heat during the first stages of the oxidation by passing dilution beingso proportioned asto prevent said spent oxids rising-above 120 Fahrenheit.

used in purifying gas which consists in producing a-closed circulation of thermally-tem-. pered, diluted air therethrough, the temperheit in temperature.

In testimony whereof I afiix my signature in the presence of two witnesses.

' HENRY DOHERTY.

Witnesses: I

RoeER's H. LYON, K. P. MCELROY.

11.. The process of recovering spent oxids above 120 ahrening and dilution being regulated to re'vent said spent oxids rising 

